| Solidification microstructures can be refined and casting defects can be reduced in the application of ultrasonic vibration to light alloy melt due to the special metallurgical effects of ultrasonic wave. Materials selection and structure design of ultrasonic radiator is vital for promoting the effect of ultrasonic. Ultrasonic radiators of three materials were designed according to the special desire of the casting technology of aluminum alloy. Meanwhile, the vibration performance of radiators was measured by physical device and tested by experiment. This study was conducted as follows:1) Ti-alloy â… ,â…¡ and pure graphite were selected to make ultrasonic radiators. Accordingly, their original size was confirmed by the design theory of amplitude transformer horn.2) Vibration modal of the ultrasonic vibration systems connecting different radiators was analyzed to modify the length of radiators. Besides, the output amplitude of the radiator end face was measured by laser displacement sensor. Results show that radiators of Ti-alloy I, II and pure graphite match the vibration system best when their size is134mm,132mm and74mm respectively.3) Ultrasonic casting experiment of aluminum alloy was carried out to test radiators’corrosion resistance to melt and refining effect on solidification microstructures. The results show that three radiators all take refining effect on ingot microstructures. Ti-alloy â… radiator is weaker in corrosion resistance while graphite radiator is not enough in fatigue strength. Ti-alloy â…¡radiator can be applied to semi-continuous casting technology of aluminum alloy for its strong corrosion resistance, high fatigue strength, excellent vibration transfer, long-time continuous working performance and stable grain-refining effect. |
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